The Association Between Anisometropia, Amblyopia, And Stereopsis In Children

PurposeTo investigate the effects of various types of anisometropia on visual acuity and stereopsis. To study the relationship between anisometropia, amblyopia and steropsis.MethodsTo select the anisometropic patients without strabismus 186 cases , which had no history of treatment for refractive error or amblyopi-a, no other ocular diseases. The children too young to obtain reliable visual acuity and sensory data were excluded. To select 20 normal children without anisometropia and visual acuity > 0. 8 as control group. The anisometropic patients were divided into four groups; hy-permetropic anisometropia group ( HA ) , myopic anisometropia group ( MA) , astigmatic anisometropia group ( AA) and all anisometropic patients group. Recorded the uncorrected visual acuity and cycloplegic refraction in each eye. The best corrected visual acuity and stereopsis were recorded after the pupils resumed. The test of 4 - D triptich used to exclude the microstrabismus. The visual acuity and stereopsis data were used for statistic analysis.ResultWhen HA > ID,MA >2D,AA > ID the incidence of amblyopia are 43% , 43% , 36% and the level of stereopsis significantly decreased in each group, when all types anisometropia > 3 D, the incidence of amblyopia increased to 100% and the Titmus stereopsis of all the patients were subnormal in each group. The correlation between the degree of anisometropia and the severity of amblyopia are larger than the correlation between the degree of anisometropia and the stereopsis. The correlation between the stereopsis and the severity of amblyopia are larger than the correlation between the stereopsis and degree of anisometropia.DisccusionAnisometropia is a main causes of amblyopia, it is unclear what degree of anisometropia will affect visual acuity and stereopsis, and the effects of various types of anisometropia on visual acuity and stereopsis were not equal, so we divided the anisometropic patients into four groups, our investigation result were : When HA > ID, MA >2D , AA > 1D The incidence of amblyopia are significantly increased, which was equal to the David results. For all the patients, the severity of amblyopia was related to the degree of anisometropia, but the correlation were different for various types anisometropia. For the reason, maybe the mechanics of amblyopia were slightly difference to various types anisometropia.When the degree of anisometropia increase, the level of stereop-sis decreased. When anisometropia >3D, the stereopsis was nearly to absent. The correlation between the degree of anisometropia and the level of stereopsis are relatively small. Our results were little different to Halit Oguz'results through experimentally induced anisometropia. Most anisometropia companied with amblyopia in children, the naturally occurring anisometropia. was more complex than experimentally induced anisometropia. Anisometropia, amblyopia and stereopsis correlated tightly each others, anisometropia was the causes of amblyopia and subnormal stereopsis. But the correlation between anisometropia and amblyopia was strong relatively. However the stereopsis was tightly correlated with the severity of amblyopia.Conclusion( 1) HA > 1D, MA > 2D, AA > 1D The incidence of amblyopia were significantly increased and the level of stereopsis decreased. When anisometropia > 3D, the incidence of amblyopia increased to 100% and all the Titmus stereopsis were subnormal in each group.(2) The correlation between the degree of anisometropia and the severity of amblyopia was stronger than the correlation between the degree of anisometropia and the stereopsis. The correlation between the stereopsis and severity of amblyopia was stronger than the correlation between the level of stereopsis and the degree of anisometropia.